UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555
July 26, 1989
Information Notice No. 89-57: UNQUALIFIED ELECTRICAL SPLICES IN
VENDOR-SUPPLIED ENVIRONMENTALLY
QUALIFIED EQUIPMENT
Addressees:
All holders of operating licenses or construction permits for nuclear power
reactors.
Purpose:
This information notice is being provided to alert addressees to a potential
problem involving unqualified electrical splices in vendor-supplied environ-
mentally qualified (EQ) equipment. It is expected that recipients will review
the information for applicability to their facilities and consider actions, as
appropriate, to avoid similar problems. However, suggestions contained in
this information notice do not constitute NRC requirements; therefore, no
specific action or written response is required.
Description of Circumstances:
On June 5, 1989, the licensee for the Cooper Nuclear Station (CNS) reported to
the NRC the finding of unqualified splices within conduits on vendor-supplied
instrument racks. The racks contain wire junction boxes and Barton differen-
tial pressure indicating switches (DPISs). A piece of flexible conduit runs
between the junction box and a condulet mounted on the DPIS (See Attachment
1). The flexible conduits vary in length from 2 to 10 feet. The unqualified
splices consisted of wirenuts, insulated butt crimps, or Scotch tape splices.
This problem was discovered during an unrelated walkdown inspection that was
being performed as part of an instrument upgrading process for Regulatory
Guide 1.97, "Instrumentation for Light-Water-Cooled Nuclear Power Plants to
Assess Plant and Environs Conditions During and Following an Accident." The
racks were manufactured by HUICO Incorporated of Pasco, Washington, and
supplied as a unit by the General Electric Company during initial plant
construction.
Discussion:
The only wiring performed by the licensee during initial plant construction
was that from the field to the rack-mounted junction boxes. During previous
EQ walkdown inspections of plant equipment, the licensee inspected the
junction boxes only to verify the existence of qualified wiring. The licensee
did not inspect the cable terminations in the DPISs because such an inspection
would
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. IN 89-57
July 26, 1989
Page 2 of 2
have affected the EQ integrity of the DPISs and because only a short run of
wire was involved. It was assumed that the qualified wire in the junction
boxes continued to the DPIS terminal strips, but unqualified splices were
found instead. These splices were not indicated on any plant drawings.
The licensee performed a 100-percent walkdown inspection of all instrument
racks and believes that the problem is confined to approximately seven racks.
A review of maintenance records indicated that about four of the DPIS instru-
ments were replaced. As this replacement only involved disconnection of leads
at the terminal strip located inside the instrument, the unqualified splices
remained undetected. The results of the licensee's investigation indicate
that the unqualified splices are restricted to the specific instrument racks
manufactured by HUICO. The investigation also indicates that the unqualified
splices existed in the conduits when the racks were delivered to CNS.
No specific action or written response is required by this information notice.
If you have any questions about this matter, please contact the technical
contact listed below or the Regional Administrator of the appropriate regional
office.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contact: Thomas F. Stetka, Region IV
(817) 860-8247
Attachments:
1. Figure 1, "Typical Junction Box and Barton Switch Arrangement"
2. List of Recently Issued NRC Information Notices
. Attachment
IN 89-57
July 26, 1989
Page 1 of 1
LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
______________________________________________________________________________
Information Date of
Notice No._____Subject_______________________Issuance_______Issued to_________
89-56 Questionable Certification 7/20/89 All holders of OLs
of Material Supplied to the or CPs for nuclear
Defense Department by Nuclear power reactors.
Suppliers
89-45, Metalclad, Low-Voltage 7/6/89 All holders of OLs
Supp. 1 Power Circuit Breakers or CPs for nuclear
Refurbished With Substandard power reactors.
Parts
89-55 Degradation of Containment 6/30/89 All holders of OLs
Isolation Capability by a or CPs for nuclear
High-Energy Line Break power reactors.
89-54 Potential Overpressurization 6/23/89 All holders of OLs
of the Component Cooling or CPs for nuclear
Water System power reactors.
89-53 Rupture of Extraction 6/13/89 All holders of OLs
Steam Line on High or CPs for nuclear
Pressure Turbine power reactors.
88-46, Licensee Report of 6/8/89 All holders of OLs
Supp. 3 Defective Refurbished or CPs for nuclear
Circuit Breakers power reactors.
89-52 Potential Fire Damper 6/8/89 All holders of OLs
Operational Problems or CPs for nuclear
power reactors.
89-51 Potential Loss of Required 5/31/89 All holders of OLs
Shutdown Margin During or CPs for nuclear
Refueling Operations power reactors.
88-88, Degradation of Westinghouse 5/31/89 All holders of OLs
Supp. 1 ARD Relays or CPs for nuclear
power reactors.
89-50 Inadequate Emergency 5/30/89 All holders of OLs
Diesel Generator Fuel or CPs for nuclear
Supply power reactors.
______________________________________________________________________________
OL = Operating License
CP = Construction Permit